Roller burnishing machine and method



Jan. 25, 1966 Q, CORY ETAL ROLLER BURNISHING MACHINE AND METHOD 4 Sheets-Sheet 1 I radar-c6014 @l figwrmrz M P 5 MO Filed June 5 Jan. 25, 1966 o. L. CORY ETAL ROLLER BURNISHING MACHINE AND METHOD 4 Sheets-Sheet 2 Filed June 5 1962 Jan. 25, 1966 CORY ETAL ROLLER BURNISHING MACHINE AND METHOD 4 Sheets-Sheet 5 Filed June 5 1962 0% @2562 awmf .Llulz Jan. 25, 1966 o. L. CORY ETAL ROLLER BURNISHING MACHINE AND METHOD Filed June 5, 1962 WWI" QZzMZrCQw Odw aid;

United States Patent ROLLER BURNISHING MACHINE AND METHOD Oda L. Cory, 1168 Indian Creek Road, and Dale E. Bowman, 142 S. Traub Ave., both of Indianapolis, Ind. Filed June 5, 1962, Ser. No. 200,131 4 Claims. (Cl. 2990) This invention relates in general to metal-working apparatus, and more particularly to a new and improved machine and process for finishing a pair of spaced-apart opposed surfaces. 7

In the crankshaft manufacturing field it has been found desirable and necessary to provide extremely smooth thrust walls adjacent the journal portions of the shaft. In the past these walls were finished by essentially a grinding and polishing operation. The surfaces thus created have proven unsatisfactory for several reasons. For example, it has been found that a surface finished by a grinding wheel often contains microscopic surface tear-s caused by the minute sharp points of the grinding wheel. Another disadvantage of the grinding operation is that the grinding wheel exhibits a tendency to wear out quite readily, thus necessitating frequent wheel changes, which results in a prohibitively expensive operation. Furthermore it has been noted that polishing does not always produce a sufficiently smooth surface, since often emery impregnations are found in the polished surfaces. The general purpose of this invention is therefore to provide an extremely smooth surface which possesses none of the afore-desoribed disadvantages. To obtain this the present invention contemplates the use of a unique tool which roller burnishes the surfaces in a cold-working operation to produce a mirror-like finish.

An object of the present invention is the provision of a machine which will produce a superior finish on a pair of spaced-apart parallel walls in a short period of time.

Another object of the invention is to provide an improved surface finish by compressing and compacting the surface rather than removing material from the surface.

A further object of the invention is the provision of an improved crankshaft in which the bearing thrust walls are parallel to each other and perpendicular to the longitudinal axis of the crankshaft.

Still another object is the provision of an improved method for providing a superior finish on a pair of spaced-apart opposed walls which lends itself to present day rapid manufacturing processes.

Yet another object of the present invention is to provide an improved cold-rolling tool which is engageable with the thrust walls of a crankshaft while the crankshaft is being rotated in a turning machine such as a lathe.

A still further object of the invention is the provision of a machine for finishing parallel spaced-apart surfaces which minimizes the danger of ma-rring the surface finish after the operation is complete.

Other object-s and advantages of the invention will hereinafter become more fully apparent from the following description of the annexed drawings, which illustrate a preferred embodiment, and wherein:

FIGURE 1 is a plan view of a preferred embodiment of the invention;

FIGURE 2 'is a section view taken along the line 22 FIGURE 1;

FIGURE 3 is a rear elevational view of the apparatus illustrated in FIGURE 1;

FIGURE 4 is a fragmentary view of the finishing tool of the present invention in the non-working position;

FIGURE 5 is a view similar to FIGURE 4, but showing the finishing tool in the working position;

FIGURE 6 is a plan view showing the rollers utilize in the finishing tool in the working position;

3,230,603 Patented Jan. 25, 1966 FIGURE 7 is a side-elevational view of the apparatus I shown in FIGURE 6;

FIGURE 8 is a sectional view taken along the line 88 of FIGURE 1; and

FIGURE 9 is a sectional view taken along the line 9+9 of FIGURE 2.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGURE 1 a crankshaft indicated generally by reference character 10. Crankshaft 10 is the type that is conventionally used in internal combustion engines and comprises generally, bearing portions 11 and longitudinally spaced and eccentrically disposed connecting rod journal portions 12. The end portions 13 and 14 of crankshaft 10 are suitably supported between the head stock 15 and tail stock 16 of a conventional turning machine, such as a lathe or the like.

Referring now to FIGURE 2, the frame 17 of the finishing tool is shown suitably mounted upon the bed 18 of the aforementioned turning tool. A pair of apertured uprights 19 and 20 are secured to the end portions of frame 17, and extend upwardly therefrom. A pair of cylindrically-shaped rails 21 and 22 extend between uprights 19 and 29, and are mounted in the apertures which are provided therein. Rails 21 and 22 are positioned so that their center lines lie in a plane which is parallel to the longitudinal axis of crankshaft 10. A suitably apertured slide member 23 is mounted upon rails 21 and 22 for reciprocating movement toward and away from the crankshaft 10.

Upright 19 is provided with a threaded hole adapted to receive screw 24, which operates as an adjustable stop means and is engageable with slide 23 to determine the position of slide 23 with respect to crankshaft 10.

A bracket 25 is secured to the outwardly-directed face of upright 20 by set screws 26 or the equivalent. Bracket 25 is provided with an outwardly projecting lug 27 having a pair of apertured ears 28 and 29. Ears 28 and 29 have pivotally associated therewith locking means indicated generally at 30, the purpose of which will hereinafter become more fully apparent.

A mounting plate 40 is fixedly secured to the upper surface of slide 23. Mounting plate 40 is provided with a transversely extending groove, in which the key 43 of holder 42 is seated. Holder 42 is secured to slide 23 by screws 44, which pass through threaded openings in holder 42, plate 40, and slide 23.

Plate 40 is provided with an outwardly extending apertured ear portion 45. A pair of Connecting links 31 and 32 are pivotally connected at their forwardly extending end to ear 4'5, and at their rearwardly extending end to the head portion of clevis 33. A cam member 35 is piv 'otally connected at one end to ear 29, and is apertured adjacent its other end for sliding movement along the threaded portion 34 of clevis 33. Nuts 36 are provided to secure cam 35 to a predetermined fixed point along clevis portion 34. Handle 37 is provided with a pair of forwardly extending arms 38, which are pivotally secured to ear 28. With particular reference to FIGURE 2 it will be apparent that as handle 37 is lifted, surface 39 will engage cam member 35 and thereby lock slide 23 against stop member 44 through the inter-action of clevis 33, links 31 and 32, and plate 40.

Holder 42 is provided with a bore 46 extending longitudinally theret-hrough, in which a substantially cylindri cally-shaped member 50 is pivotally received. Member 50 is provided with an annular flange 51 adjacent its forwardly extending tool receiving end, which is engageable with the flat face 47 of holder 42 to prevent member 50 from moving rearwardly in here 46. Member 50 is prevented from moving forwardly through bore 46 by the engagement of retainer ring 52 with the rearward surface 48 of holder 42. Retainer ring 52 is secured to the shoulder portion 54 of member 50 by set screws 55 or the like.

The rearwardly extending end of member 50 includes a portion of reduced diameter 56, which is provided with a transversely extending threaded hole adapted to receive the threaded end portion 58 of handle 57. As is best seen in FIGURE 3, an ovoid lug 60 is secured to holder 42 adjacent one corner of surface 48. Lug 60 is provided with a threaded aperture adapted to receive screw 61, which acts as an adjustable stop means to limit the upward movement of handle 57. A screw 62 is threaded into shelf 49 of holder 42 to provide an adjustable stop means to limit the downward movement of handle 57.

The forwardly extending end of member 50 is provided with an enlarged cage carrier portion indicated generally at 63. As is best seen in FIGURE 8, the forwardly ex tending end of member 50 is substantially semi-cylindrical in cross section having a flattened bottom surface 64. Surface 64 is provided with a longitudinally extending keyway 65, in which the key formed on the bottom of low-er roller carrier member 66 is seated. Lower carrier 66 is secured to member 50 by a pair of screws 67 which are threaded into holes 68 provided in portion 63. Upper carrier 69 is formed integrally with member 50 and extends forwardly of portion 63. As is best seen in FIG- URE 4 and FIGURE 5, upper and lower carriers 69 and 66 respectively, are substantially identical in cross section, each having tapered side faces 70, the significance of which will hereinafter become more obvious.

Carriers 66 and 69 are provided with keyways 71 and 72 on their inwardly directed surfaces, in which are seated keys formed on upper and lower cage sections 74 and 73 respectively. Each cage section is provided with a pair of substantially semi-cylindrically shaped cut-out portions which extend longitudinally thereof, in which rollers 75 and 76 are rotatably mounted. Rollers 75 and 76 are each provided with an annular groove 77 which is adapted to receive shoulder screw 78, that serves to retain rollers 75 and 76 in proper position and also serves to bind cage sections 73 and 74 together. As is best seen in FIGURE 9, the radius of annular grooves 77 is slightly larger than the radius of retainer screw 78, which allows rollers 75 and 76 to rotate over retainer screw 78 with little or no friction.

Upper carrier 69 is provided with a downwardly projecting portion 80 to define a wall section 81 against which the rearwardly extending ends of rollers 75 and 76 are seated. Surface 81 is hardened and ground to take up the back thrust of rollers 75 and 76 as will hereinafter become more fully apparent.

In operation, the crankshaft 10, or piece to be worked upon, is placed in the turning machine, and rotary motion is imparted thereto. The finishing tool is then advanced toward the work with the cage carrier in the position illustrated in FIGURE 4. It is important to note that with the parts in a position illustrated in FIGURE 4 handle 57 rests against adjustable stop 61 which is set at a predetermined point that allows tapered walls 70 to pass between the workpiece walls 11'. In this position the centers of rotation of rollers 75 and 76 lie in a plane which is disposed at an angle to the rotational axis of crankshaft 10, so that rollers 75 and 76 are freely insertable between walls 11'. The finishing tool is advanced to a predetermined point as determined by the engagement of slide 23 with stop 24 which positions rollers 75 and 76 at the proper working depth. Locking means 30 are then engaged to secure slide 23 in this position. The operator then lowers handle 57 against stop 62 so that the center lines of rollers 75 and 76 are disposed in a plane substantially parallel to the rotational axis of crankshaft 10. Since the distance between the outer peripheries of rollers 76 and 75 is greater than the distance between walls 11, when the cage carrier is rotated to the position shown in FIGURE 5, the rollers will engage the Wall surfaces and will themselves be rotated because of the frictional engagement with the walls. Rollers 75 and 76 will rotate in a substantially friction-free manner, since their only contact is a theoretical line-to-line contact With each other. As a result, a tremendous lateral pressure is exerted against walls 11, serving to displace and compress the wall surface.

It is also important to note that the centers of rotation of rollers 75 and 76 are disposed in a plane which is vertically spaced from the center of rotation of crankshaft 10. This causes a slight sliding or burnishing action between roller 75 and 76, and wall portions 11, which results in an extremely smooth mirror-like finish. With the crankshaft 1t rotating in a counterclockwise direction, as viewed in FIGURE 2, rollers 75 and 76 are disposed below the center line of crankshaft 10 so that the thrust imparted thereto is taken up by hardened wall 81. As can be readily understood, if it is desired to rotate crankshaft 10 in a clockwise direction, rollers 75 and 76 are positioned within their center lines lying in a plane spaced above the center of rotation of crankshaft 10.

The rollers are allowed to dwell in the position illustrated in FIGURE 5, until the rolling process is concluded, and then handle 57 is rotated upward against stop 61, and locking means 30 are disengaged to enable the finishing tool to be withdrawn from between the finished surfaces. It should be understood that because of the tapered walls 70 and the predetermined setting of stop 61, there is little or no danger of marring the finished surfaces when withdrawing the tool.

In order to insure a proper finish, it is important that rollers 75 and 76 be identical in shape, each having a diameter which is one-half of the finished distance between walls 11'. It is also important to note that the center of rotation of member 50 should be in substantial alignment with the line of contact between rollers 75 and 76.

From the foregoing it should be apparent that the device has great facility in producing a superior finish upon parallel spaced-apart crankshaft bearing thrust Walls. It should also be apparent that the use of this invention is not limited thereto, and in fact would have great utility in roller burnishing any pair of spaced-apart walls. Furthermore, various modifications of the device are contemplated and may obviously be resorted to by those skilled in the art without departing from the spirit and the scope of the invention, as hereinafter defined by the appended claims.

What is claimed is:

1. Apparatus for finishing spaced-apart surfaces formed on a rotatably mounted workpiece comprising: a holder, a carrier pivotally mounted in said holder for limited pivotal movement about an axis perpendicular to the axis of said workpiece, limit means associated with said holder adapted to regulate the pivotal movement of said carrier, a pair of rollers rotatably mounted on said carrier, the distance between the outer dimensions of said rollers being greater than the distance between said surfaces so that said rollers are rotated by the rotation of said workpiece when they are disposed between said surfaces, means for pivoting said carrier to position said rollers between said surfaces, the axis of said rollers being vertically spaced from the axis of said workpiece whereby said surfaces are burnished when said workpiece is rotated.

2. A device for compressing lateral spaced-apart flat surfaces formed on a rotatably mounted workpiece comprising: a frame, a holder slidably mounted on said frame for movement at substantially right angles to the axis of said workpiece, adjustable stop means on said frame engageable with said holder to limit the movement of said holder with respect to said workpiece, locking means on said frame adapted to retain said holder against said stop means, a carrier pivotally mounted in said holder for limited clockwise and counterclockwise rota-tion between said surfaces about an axis perpendicular to the rotatable axis of said workpiece, limit means associated with said holder adapted to control the pivotal movement of said carrier, a pair of generally cylindrically-shaped rollers rotatably mounted on said carrier, said rollers being positioned in side by side edge contacting relation and having their axes disposed at substantially right angles to the axis of said member, the distance between the outerdimensions of said rollers being greater than the distance between said surfaces so that said rollers are rotated by contact with said surfaces of the rotating workpiece when the carrier is pivoted against its limit means, the axes of said rollers being vertically spaced from the axis of said workpiece whereby said surfaces are burnished when said workpiece is rotated.

33. A device for finishing laterally spaced-apart fiat surfaces of a workpiece which is rotating about its axis, comprising: a holder, 3. carrier rotatably positioned on said holder for clockwise and counterclockwise rotation about an axis substantially perpendicular to the axis of said workpiece, a pair of generally cylindrical rollers rotatably mounted on said carrier in side by side contacting relation with each having its axis parallel to the axis of said carrier, the distance between the outer dimensions of said rollers being greater than the distance between said fiat surfaces, means for rotating said carrier about its axis whereby said rollers and surfaces are placed in relative compressed relation between said surfaces, and said rota tion of said crankshaft imparts rotation to said rollers to compress and finish said surfaces.

4. Apparatus for finishing spaced-apart surfaces formed on a rotatably mounted workpiece comprising: a holder, a pair of rollers rotatably mounted in said holder, the distance between the outer dimensions of said rollers being greater than the distance between said surfaces so that said rollers are rotated by the rotation of said workpiece when they are disposed between said surfaces, the axis of said rollers being vertically spaced from the axis of said workpiece whereby said surfaces are burnished when said workpiece is rotated, said holder being provided with means for inserting said rollers between said surfaces and means for withdrawing said rollers from between said surfaces without contacting said surfaces.

References Cited by the Examiner UNITED STATES PATENTS 235,921 12/1880 Way 2990 2,522,084 9/1950 Baruch 29-90 2,841,861 7/1958 Williams 2990 2,992,470 7/ 1961 Miller 291.1

RICHARD H. EANES, JR., Primary Examiner. 

1. APPARATUS FOR FINISHING SPACED-APART SURFACES FORMED ON A ROTATABLY MOUNTED WORKPIECE COMPRISING: A HOLDER, A CARRIER PIVOTALLY MOUNTED IN SAID HOLDER FOR LIMITED PIVOTAL MOVEMENT ABOUT AND AXIS PERPENDICULAR TO THE AXIS OF SAID WORKPIECE, LIMIT MEANS ASSOCITED WITH SAID HOLDER ADAPTED TO REGULATE THE PIVOTAL MOVEMENT OF SAID CARRIER, A PAIR OF ROLLERS ROATATBLY MOUNTED ON SAID CARRIER, THE DISTANCE BETWEEN THE OUTER DIMENSIONS OF SAID ROLLERS BEING GREATER THAN THE DISTANCE BETWEEN SAID SURFACES SO THAT SAID ROLLERS ARE ROTATED BY THE ROTATION OF SAID WORKPIECE WHEN THEY ARE DISPOSED BETWEEN SAID SURFACES, MEANS FOR PIVOTING SAID CARRIER TO POSITION SAID ROLLERS BETWEEN SAID SURFACES, THE AXIS OF SAID ROLLERS BEING VERTICALLY SPACED FROM THE AXIS OF SAID WORKPIECE WHEREBY SAID SURFACES ARE BURNISHED WHEN SAID WORKPIECE IS ROTATED. 